CN102300662B

CN102300662B - Reciprocating electric tool

Info

Publication number: CN102300662B
Application number: CN201080005984.2A
Authority: CN
Inventors: 中村瑞穗; 安保公敬; 今井辉雄
Original assignee: Hitachi Koki Co Ltd
Current assignee: Machine holding company
Priority date: 2009-01-30
Filing date: 2010-01-20
Publication date: 2014-12-03
Anticipated expiration: 2030-01-20
Also published as: DE202010018130U1; WO2010087351A1; EP2391472A1; CN102300662A; DE202010018160U1; US20110273117A1; JP5376216B2; US8922141B2; EP2391472B1; JP2010173039A

Abstract

The invention provides a reciprocating electric tool (1) having a brushless motor (3), a plunger (52), and control means (6). The plunger (52) is driven by the brushless motor and reciprocating between two dead centers. A end bit (7) is mounted to one end of the plunger in a reciprocating direction. The control means (6) controls a rotational speed of the brushless motor based on a position of the plunger.

Description

Reciprocating electric tool

Technical field

The present invention relates to a kind of reciprocating electric tool, relate more specifically to a kind of portable reciprocating electric tools that is provided with the end cutter head (end bit) such as blade, for passing through the reciprocating motion cut workpiece of end cutter head.

Background technology

Traditional reciprocating electric tool, such as jigsaw, comprises blade and the substrate that directly contacts workpiece.Blade is designed to from substrate outstanding, moving relative to substrate in vertical direction, thereby allows cut workpiece.

Patent documentation

PLT1: Japanese Patent Application Publication No.2004-1363

Summary of the invention

The technical problem solving

In this traditional reciprocating electric tool, carrying out while moving back and forth (at jigsaw in the situation that be to move both vertically), requiring piston that end cutter head (blade) and blade be installed on it in two dead points (top dead-centre and bottom dead centre) its direction of motion of locating to reverse.At these dead point places, the direction of motion of blade (piston) is forced to significantly turn round, and causes vibration and noise to occur.

In addition, in the time of delivery reciprocating electric tool, because blade is pretty troublesome thing, user must firmly grasp blade for blade is pushed to substrate, or manipulation operations switch is so that blade (piston) stops at the dead point place (being top dead-centre in the situation that of jigsaw) that blade is retracted maximum.On the contrary, in the time of allowing blade replacement more, for from substrate pull-out blade, user need to firmly grasp blade, or manipulation operations switch is so that blade can be positioned at wherein outstanding maximum another dead point place (being bottom dead centre place in the situation that of jigsaw) of blade, to be convenient for changing blade.Every kind of situation all causes low workability.

Technical scheme

Consider foregoing problems, the object of this invention is to provide a kind of reciprocating electric tool, have enhancing workability, can realize low vibration and low noise.

In order to realize above-mentioned and other object, the present invention be characterised in that there is brushless motor, the reciprocating electric tool of piston and control device.Piston is driven by brushless motor and moves back and forth between two dead points.End cutter head is installed to one end of piston on reciprocating direction.The rotating speed of the Position Control brushless motor of control device based on piston.

Had this configuration, the position of piston can easily be controlled by brushless motor.

In the reciprocating electric tool with above configuration, preferably, be provided for detecting the checkout gear of piston position.

Use this configuration, because the detection of piston position can become easier, the more easily position of control piston and speed.

Preferably, checkout gear is the sensor that detection piston reaches precalculated position.

Adopt this configuration, can detect more accurately with simple configuration the position of piston.Therefore, can be with position and the speed of higher precision control piston.

Preferably, control device is according to the slow down rotating speed of brushless motor of the position of piston.

Use this configuration, can be according to the position deceleration brushless motor of piston, thus reduce noise and vibration.

Preferably, in the time that piston moves to another dead point from a dead point, the slow down rotating speed of brushless motor of control device.

Adopt this configuration, the brushless motor that can slow down, thereby the noise and vibration while making it possible to reduce the moving direction that changes piston before the direction of motion revolution of piston.

Preferably, when piston arrives approaches and just when the position before any dead point, the slow down rotating speed of brushless motor of control device.

Use this configuration, the brushless motor that can slow down that can be before the direction of motion of piston is switched, thereby noise and vibration while reducing the direction that switching piston moves.

Preferably, when piston reaches close to arbitrary dead point with just when the position before arbitrary dead point, the slow down rotating speed of brushless motor of control device, and when piston is by after arbitrary dead point, control device is accelerated the rotating speed of brushless motor.

Use this configuration, the brushless motor that can slow down before the direction of motion of piston is switched, thereby reduce switching piston move direction time noise and vibration.Meanwhile, motor can be accelerated subsequently, thereby keeps the ability of cut workpiece.

Preferably, decelerate position setting device is set, for be provided for the decelerate position of the rotating speed of brushless motor according to the position of piston.Control device is according to the slow down rotating speed of brushless motor of the decelerate position that arranged by decelerate position setting device.

Adopt this configuration, the decelerate position of brushless motor can be set arbitrarily.Therefore, decelerate position can be set to the position of vibration and noise producing maximum.

Preferably, brushless motor is maintained deceleration regime by control device, until piston is by arbitrary dead point.

This disposing while helping reduce piston divertical motion direction produces and vibrates and noise.

Preferably, after the rotating speed of brushless motor reduces, in control device predetermined time cycle, the rotation of brushless motor is maintained to deceleration regime.

Adopt this configuration, at the appointed time in the cycle, brushless motor is remained to deceleration, thereby cause the vibration and the noise that reduce.

Preferably, storage device is set, the multiple decelerate position information that arrange for storing decelerate position setting device.The decelerate position of control device based on being arranged by decelerate position setting device calculated for the cycle very first time in deceleration regime by brushless motor, and maintain the cycle very first time in cycle as slowing down and be stored in storage device what calculate, and control device maintains deceleration regime by brushless motor before maintaining period expires being stored in deceleration in storage device.

Adopt this configuration, decelerate position can be set to noise and vibration and be considered to produce maximum position.In addition, in the time of vibration and noise continuation, brushless motor is maintained to deceleration.Therefore, can further realize the reduction of noise and vibration.

Preferably, control device calculates the second time cycle that reaches first dead point after the rotating speed of brushless motor slows down based on decelerate position information, and the second time cycle calculating is stored in storage device, and the piston that is rotated in of brushless motor passes through to be accelerated behind dead point.

Use this configuration, brushless motor is occurred to slow down near the most intensive dead point by hypothesis at noise and vibration.

Preferably, speed setting device is set, for the rotating speed of brushless motor is set.And, storage device is set, the multiple decelerate position that arrange for storing decelerate position setting device.The rotating speed of the decelerate position of control device based on the setting of decelerate position setting device and the brushless motor that arranged by speed setting device calculates for brushless motor is maintained in the deceleration of deceleration regime and held time the cycle, and the deceleration cycle of holding time calculating is stored in storage device.

Adopt this configuration, can decelerate position be set according to the speed that arranges of brushless motor.Therefore, vibration and noise can reduce and regardless of the setting speed of brushless motor.

Preferably, speed setting device is set, for the rotating speed of brushless motor is set.And, storage device is set, for the signalization based on from speed setting device and decelerate position setting device, pre-storedly hold time the cycle for the deceleration that brushless motor is maintained to deceleration regime.Control device is according to the slow down rotation of brushless motor of the deceleration cycle of holding time in storage device of being stored in.

Adopt this configuration, can be according to the rotating speed of brushless motor and the pre-stored decelerate position of decelerate position information.Therefore,, no matter reduce except brushless motor speed being set noise and vibration, control device needn't be carried out calculating in the time that the speed of brushless motor is set at every turn.

Preferably, storage device is set, for storing the desired speed of brushless motor.When the rotating ratio of the brushless motor being arranged by speed setting device is stored in desired speed in storage device when low, control device maintains fixing rotating speed by the rotation of brushless motor and no matter from the output of decelerate position setting device.

Use this configuration, in the time that brushless motor rotating speed slows down, particularly when rotating speed is while being the slowest, do not control brushless motor and slow down.Therefore, the ability of reciprocating electric tool cut workpiece can be maintained.

Preferably, reset apparatus is set, the decelerate position of the brushless motor having been arranged by decelerate position setting device for resetting.

Adopt this configuration, decelerate position can be set to easily and be considered to produce larger noise and such position of vibration.

Preferably, control device control brushless motor, to stop at piston near a dead point.

Use this configuration, allow piston to be parked in wherein piston from the most outstanding position of the substrate of reciprocating electric tools, so as can be easily allowing blade replacement more.Can also allow piston to be parked in the position that piston-retraction is maximum.Therefore,, in the time that user carries reciprocating electric tool, piston and end cutter head are left user alone.

Preferably, stop position switching device shifter is set, for the stop position of piston is switched to another dead point.

Adopt this configuration, can select piston stop position according to user's expection object, cause the workability of improving.

Preferably, stop position setting device is set, for the stop position of piston is set.Control device control piston, to stop at piston the pre-position being arranged by stop position setting device.

This configuration makes user, according to user's desired use, piston be stopped to assigned address, for example, and in order to carry the object of reciprocating electric tool or replacing end cutter head.Therefore, strengthened workability.

Preferably, stop position setting device output signal is to control device, and described signal is for stopping at piston near arbitrary dead point.Control device control brushless motor, stops piston with basis from the output signal of stop position setting device.

Use this configuration, in the time that piston stops in the most outstanding position, can be so that change end cutter head.In the time that piston stops at maximum retraction position place, the portability of reciprocating electric tool is not damaged.

In addition, traditionally, the stop position of piston can not be specified by user.Therefore, the part of mounting end cutter head need to have large scale thereon, no matter the position of the piston so that end cutter head can be replaced.On the contrary, can be specified by user because reciprocating electric tool according to the present invention makes stop position, therefore the part of mounting end cutter head can be made compact thereon, thereby realizes the minimizing of reciprocating electric tools in size and weight.

Preferably, stop position setting device output switching signal is to control device, and described switching signal is for being switched to by the stop position of piston the position that approaches another dead point.Control device is according to switching signal control brushless motor.

The position that this configuration allows user to select piston to stop according to the predetermined object of user, causes the workability of improving.

Preferably, device for detecting rotational position is set, for detection of the position of rotation of brushless motor.And storage device is set, for the position of the position of rotation corresponding to brushless motor based on the piston position data relevant with the position of piston to the position of rotation of brushless motor that prestore.The position of rotation of the brushless motor detecting based on device for detecting rotational position and be stored in the position data in storage device, control device calculates the position of piston.

Adopt this configuration, can detect according to the position of rotation of brushless motor the position of piston.Therefore, there is no need to adopt the device for detection of the position of piston.

Preferably, storage resetting means, for resetting to the position of rotation of brushless motor and being stored in the position data that the position of piston of storage device is relevant.

Use this configuration, as long as there is mistake in relation betwixt, user's relation between the position of the piston stored in the position of rotation of brushless motor and storage device of just can resetting.

Preferably, storage is set and reconfigures device, for reconfiguring to the position of rotation of brushless motor and being stored in the position data that the position of piston of storage device is relevant.

Use this configuration, because can store exactly the relation between the position of rotation of brushless motor and the position of piston, therefore can accurately control brushless motor according to the position of piston.

In addition, can be provided for providing the battery of electric power to brushless motor.

This structure has increased the portability of reciprocating electric tool, thereby improves its workability.

In addition, the AC power that supplies power to brushless motor can be set.

Use this configuration, user can operate this reciprocating electric tool of running within the longer time cycle, thereby increases its workability.

The present invention also provides a kind of reciprocating electric tool, has brushless motor, piston and control device.Piston is driven by brushless motor and is reciprocal between two dead points.End cutter head is installed to one end of piston on reciprocating direction.Control device for based on piston the position during the reciprocation period of piston control the rotating speed of brushless motor.

Adopt said structure, during the reciprocation period of piston, can be easily by the position of brushless motor control piston.

The present invention also provides a kind of reciprocating electric tool, has brushless motor, piston and control device.Piston is driven by brushless motor and is reciprocal between two dead points.End cutter head is installed to one end of piston on reciprocating direction.Control device control brushless motor, to stop at piston predetermined stop area.

Adopt said structure, can be easily by the position of brushless motor control piston.In general, the stop position of piston is precalculated position, such as each dead point.In addition, any position (as the adjacent domain to precalculated position) and comprise as described in the presumptive area in precalculated position can be selected as the stop position of piston.

Beneficial effect

According to the present invention, can strengthen workability, vibration and noise are all suppressed at low-level simultaneously.

Brief description of the drawings

In the drawings:

Fig. 1 is according to the sectional view of the reciprocating electric tool of the embodiment of the present invention;

Fig. 2 shows according to the view of the drive unit of the reciprocating electric tool of the present embodiment and blade;

Fig. 3 is according to the circuit theory diagrams of the control module of the reciprocating electric tool of the present embodiment;

Fig. 4 is that explanation is according to the chart of the position of the piston of the reciprocating electric tool of the present embodiment and the relation between the time;

Fig. 5 is according to the sectional side view of the reciprocating electric tool of the present embodiment, and wherein blade is positioned at its upper dead center position place;

Fig. 6 shows according to the flow chart of the driving control of the piston of the reciprocating electric tool of the present embodiment;

Fig. 7 is according to the control block diagram of the reciprocating electric tool of the present embodiment; With

Fig. 8 is according to the control block diagram of the reciprocating electric tool of the variation of the present embodiment.

Detailed description of the invention

Hereinafter, with reference to Fig. 1 to 7 explanation according to the reciprocating electric tools of the embodiment of the present invention (jigsaw) 1.

As shown in Figure 1, jigsaw 1 comprises shell 2, motor 3, substrate 4, drives section 5, control module 6 and the blade 7 as end cutter head.Jigsaw 1 moves up in the side specifying, and uses blade 7 cut workpiece (not shown)s simultaneously.In the following description, the direction that jigsaw 1 moves in the time of cut workpiece will be called as " cut direction ".In cut direction, jigsaw 1 advance towards a side will be called " forward ".In addition, vertical (from top to bottom) direction is defined as follows: be called " downwards " direction from shell 2 towards the direction of pedestal 4, and be called " upwards " from pedestal 4 towards the direction of shell 2.In addition, level (left-to-right) direction is by the direction being defined as perpendicular to vertical direction and cut direction.

Shell 2 is chassis configuration, and it is made up of the material such as aluminium.Shell 2 is formed with for making user can hold the handle 21 of jigsaw 1 in upper end thereafter.The trigger switch 22 that comprises trigger 22A is arranged on the base end part of handle 21, so that user can operate trigger 22A to control to the power supply of motor 3.

Battery 23 is removably mounted in jigsaw 1, in the position backward in cut direction of handle 21.Battery 23 is supplied electric power to motor 3, control module 6 etc. as power source, thereby contributes to improve portability and the workability of jigsaw 1.As a kind of substitute electric power, can use outside commercial power (AC power 90) as shown in Figure 8 to replace battery 23.In this case, need to be used for alternating current to be converted to the current transformer 80 of direct current (seeing Fig. 8).Use AC power 90 to be conducive to user's long period and use jigsaw 1, cause improved workability.

In shell 2, position sensor 24 (for example proximity transducer) is arranged on the position that drives section 5 tops.Position sensor 24 detects motion and the output signal of piston 52 between two dead points (as introduced in the back) and arrives control module 6.Therefore, the position on the longitudinal direction of piston 52 answered preferred vertical and is positioned at by position sensor 24.

Motor 3 is DC Brushless Motor, for allowing control module 6 accurately to control rotating speed and the anglec of rotation of motor 3.Motor 3 is accommodated in shell 2, about centre at shell 2.Output shaft 31 is outstanding from motor 3 in the direction that is roughly parallel to horizontal direction, and pinion 31A is arranged on the end of output shaft 31.Cooling fan 32 is also arranged on output shaft 31 at its bottom place.Cooling fan 32 guides air to enter shell 2 from the air inlet port (not shown) being formed on shell 2, thereby motor 3 and control module 6 can cool down with air.

Substrate 4 is mainly made of aluminum, and forms essentially rectangular shape.Substrate 4 has reaction surface 41A, and it is relative with workpiece and contact with workpiece (plank).The longitudinal direction of the reaction surface 41A of essentially rectangular is configured to consistent with the cut direction of jigsaw 1.In this way, shell 2 is supported in substrate 4.Suppose the imaginary axis on reaction surface 41A in a horizontal direction extend and intersect with blade 7.Shell 2 is configured to move pivotally with respect to substrate 4 around this imaginary axis (pivot).

Blade 7 has cutting teeth portion and knife back portion.As shown in Figure 1, it is upper that blade 7 is arranged on piston 52 (after a while introduce), make cutting teeth portion in cutting direction upwards and forward towards, and knife back portion in cutting direction backward towards.

Drive division 5 mainly disposes crank portion 51, piston 52, power transmissioning part 53 and roller frame 54.

Crank portion 51 comprises spur gear 51A, pin 51B and main shaft 51C.Spur gear 51A is engagingly in conjunction with pinion 31A.Spur gear 51A is provided with cam 51D at its base end place.Cam 51D is in conjunction with power transmissioning part 53.Thereby the axis that pin 51B protrudes forward pin 51B from spur gear 51A extends in the rotation direction that is parallel to spur gear 51A.The pin axis of 51B and the rotation of spur gear 51A differ from one another.Main shaft 51C is fixed to shell 2 for rotatably supporting spur gear 51A.

Piston 52 forms roughly staff-like shape.Piston 5 is slidably supported in shell 2 movably, thereby the longitudinal direction of piston 52 is parallel with vertical direction.As shown in Figure 2, piston 52 comprises maintaining part 52A and acceptance division 52B.Maintaining part 52A keeps blade 7 and is arranged on piston 52 at the bottom place of piston 52.Acceptance division 52B is formed on the center of piston 52.Acceptance division 52B is formed with in the horizontal direction (left and right directions) upper groove 52B extending, in pin 51B insertion groove 52B.Pin 51B is allowed to move in the horizontal direction, vertically moves but be limited in groove 52B.Therefore, acceptance division 52B is only allowed to move both vertically in conjunction with the motion of pin 51B.In other words, pin 51B can convert moving both vertically of piston 52 to around the pivoting action of main shaft 51C.Piston 52 moves (seeing Fig. 4) in vertical direction in the stroke S of preset range.

As shown in Figure 1, power transmissioning part 53 is supported to shell 2 and in conjunction with cam 51D, thereby power transmissioning part 53 can be in vertical direction in the interior movement of shell 2.Power transmissioning part 53 has the bottom of touch roll frame 54.

Roller frame 54 disposes support 54A, roller 54B and at the upwardly extending axle 54C of right and left.Support 54A is arranged on the rear of blade 7 and can moves pivotally around axle 54C in the direction perpendicular to left and right directions.Support 54A has the top of the bottom of contact power transmissioning part 53.Therefore,, according to moving both vertically of power transmissioning part 53, support 54A moves counterclockwise and clockwise pivotly Fig. 1's.Roller 54B rotatably supports to the bottom of support 54A, contacts with the back of blade 7 simultaneously.

As shown in Figure 1, control module 6 is arranged on the rear of motor 3, so that control module 6 can be arranged in the path of the air being produced by the rotation of cooling fan 32.As introduced in the back, control module 6 comprises control circuit 61 and FET drive circuit (inverter circuit) 62.

Be described in more detail control module 6 with reference to Fig. 7 below.Motor 3 (DC Brushless Motor) comprises rotor 3A, stator 3B and stator winding (armature winding) 3C.Rotor 3A comprises the permanent magnet with the South Pole and the arctic, permanent magnet be embedded in rotor 3A and extend towards output shaft 31.Stator 3B has about hollow cylinder profile and rotor 3A is arranged in stator 3B.Stator winding 3C is arranged in stator 3B with one heart.Stator winding 3C is made up of three phase winding U, V and the W of stator 3B.Each stator winding 3C is wrapped in the groove of stator 3B by Y-connection and by insulating barrier (not showing: be made up of resin material), so that stator winding 3C is around stator 3B.

Three hole IC (hole IC) 65,66 and 67 are arranged near of rotor 3A, for detection of the position of rotation of rotor 3A.Each hole IC 65,66 and 67 is arranged in the every 60 degree places along the direction of rotation of rotor 3A.Based on the position detection signal from hole IC 65,66 and 67 outputs, FET drive circuit 62 is controlled the electric current that flows into stator winding 3C.During this time, the electric current of inflow stator winding 3C is controlled to fall within the scope of the conduction of 120 ° of electrical angles (electric angle).

As shown in Figure 7, FET drive circuit 62 comprises the thyristor 62A that six three-phase bridge connect.Thyristor 62A is made up of igbt (IGBT) Q1-Q6.Also can adopt the FET that six bridgings connect to replace thyristor 62A.Each grid of thyristor 62A (Q1-Q6) is connected to the control signal output circuit 63 of control circuit 61.On the other hand, the colelctor electrode of each thyristor 62A or emitter stage are connected to the stator winding 3C (U, V and W) of the Y-connection of motor 3.Use this configuration, six thyristor 62A drive signal (switching signal) H1-H6 to carry out switching manipulation according to the PWM inputting from control signal output circuit 63, convert the direct current that is applied to FET drive circuit 62 of battery 23 to three-phase (U phase, V phase and W phase) voltage Vu, Vv and Vw, and three-phase alternating current is applied to stator winding 3C.

Control circuit 61 is controlled motor 3 and other devices by switching signal H1-H6 being outputed to FET drive circuit 62 via control signal output circuit 63.Control circuit 61 comprises that control/computing unit 61A, rotor position detection circuit 68, speed detect circuit 69, current detection circuit 70, applied voltage arrange circuit 71, speed indicating circuit 61E and piston position testing circuit 74.

Control/computing unit 61A comprises microcomputer, for producing and will be output to the output signal of control signal output circuit 63 based on handling procedure, control data and the input signal such as motor position signal.Position relationship between output signal detection rotor 3A and the stator winding 3C of stator 3B of rotor position detection circuit 68 based on from hole IC 65,66 and 67, and the positional information of output rotor 3A is to output/computing unit 61A.Speed detect circuit 69 detects the rpm of motor 3 according to the interval of the signal from hole IC 65,66 and 67 outputs.

Current detection circuit 70 detects continuously and flows through the drive current of motor 3 and output detection signal to control/computing unit 61A.Applied voltage arranges circuit 71 the PWM dutycycle corresponding to the switching signal of output control signal is set, and described output control signal responds the drafts of trigger 22 by trigger switch 22 and produces.Speed indicating circuit 61E is according to the signal output indicated speed signal from speed setting device 72 (modulator VR) to control/computing unit 61A, and speed setting device 72 arranges the rotating speed of motor 3.Piston position testing circuit 74 detects the position of piston 52 according to the detection signal of position sensor 24.

The PWM that the output signal control thyristor 62A of circuit 71, speed indicating circuit 61E etc. is set from current detection circuit 70, applied voltage by basis drives the PWM dutycycle of signal, control/computing unit 61A controls the voltage (Vu, Vv and Vw) of the stator winding 3C that is applied to motor 3.Switch thyristor 62A by the order with regulation, control/computing unit 61A is also applied to the voltage (Vu, Vv and Vw) of stator winding 3C with the sequential control of regulation, thereby controls the rotation of motor 3.

Control/computing unit 61A also calculates the position of piston 52 based on the output signal of piston position testing circuit 74, thereby controls the rotating speed (accelerate, slow down or stop) of motor 3 according to the position 52 of piston.

Control/computing unit 61A is further connected to decelerate position setting device 76 and stop position setting device 75.Decelerate position setting device 76 specifies piston 52 in its reciprocating motion process, to need the position (α 1 and α 2 in referring to Fig. 4) of slowing down.Stop position setting device 75 arranges the position that piston 52 stops in the time that trigger switch 22 is closed.52 positions of piston based on being detected by position sensor 24 and stop position setting device 75 and decelerate position arrange 76 output signal, and control/computing unit 61A controls rotating speed and the anglec of rotation of motor 3.

The motor speed signal that arranges and export from speed indicating circuit 61E according to the output signal of the applied voltage initialization circuit 71 of the drafts corresponding to trigger 22A and by speed setting device 72, control circuit 61 changes the PWM dutycycle of the switching signal of thyristor 62A.In this way, control circuit 6 is adjusted to the power supply supply of motor 3, thereby controls the rotating speed of motor 3.In the time that trigger 22A is fully pressed down to its maximum, the rotating speed (rpm) that control circuit 61 is controlled motor 3 equals the rpm being arranged by speed setting device 72.

Control/computing unit 61A is made up of microcomputer.Microcomputer comprises CPU (not shown), ROM (storage device 64), RAM (storage device 64) and timer 78 (seeing Fig. 7).Based on handling procedure and each processed data, CPU output drive signal.ROM storage is for carrying out the control program of describing and the handling procedure of controlling data below.RAM temporarily stores such as the position relationship between piston 52 and motor 3 (rotor 3A) and the data of time cycle, and during the described time cycle, piston 52 moves back and forth and moves to any dead point with the rotating speed of regulation from decelerate position.The time that timer 78 moves to during dead point from assigned address piston 52 counts.

As shown in Figure 3, control/computing unit 61A also comprises position detection part 61B, speed controlling portion 61C and voltage control division 61D.

Position detection part 61B is connected to rotor position detection circuit 68 (speed detect circuit 69) and piston position testing circuit 74.According to the signal from these circuit outputs, the position of the position of rotation of position detection part 61B calculating motor 3 and rotating speed and piston 52.In addition, terminal voltage checkout gear 77 can be connected to position detection part 61B instead of rotor position detection circuit 68, as by introducing in the back.

Signal based on from speed setting device 72, motor speed signal, motor rotating position signal and the piston position signal from position detection part 61B, by reference to the electromotor velocity signal of the appointment from speed indicating circuit 61E output, speed controlling portion 61C determines whether the rotating speed of motor 3 becomes the electromotor velocity of appointment.

Based on the output signal from speed controlling portion 61C, voltage control division 61D exports driving signal about motor 3 to FET drive circuit 62 via control signal output circuit 63.

In the jigsaw 1 with above-mentioned configuration, when the user who is arranged on (being therefore connected to) shell 2 and jigsaw 1 when battery 23 operates trigger switch 22, motor starts to rotate.For the rotation in response to motor 3, the driving force of motor 3 is transferred to piston 52 from the output shaft 31 of motor 3 by power transmissioning part 53, thereby piston 52 is moved back and forth.Follow the reciprocating motion of piston 52, the blade 7 being arranged on piston 52 tops can cut workpiece.

Or rather, when operation is when trigger switch 22, applied voltage arranges circuit 71 and exports signal corresponding to the drafts of trigger 22A to control circuit 61.Based on this signal, control/computing unit 61A produces the switching signal for thyristor 62A, and arrives FET drive circuit 62 by control signal output circuit 63 these switching signals of output.Control/computing unit 61A thereby control motor 3, with the speed rotation of the drafts corresponding to trigger 22A, allow jigsaw 1 cut workpiece.The maximal rate of motor 3 is set to the speed being specified by speed setting device 72.

Subsequently, control circuit 61 use are passed through position of rotation and the rotating speed of rotor position detection circuit 68 and speed detect circuit 69 detection rotor 3A from the signal of hole IC 65,66 and 67.In this way, control circuit 61 is controlled the rotating speed of motor 3.Meanwhile, based on the output from position sensor 24 and piston position testing circuit 74, control circuit 61 calculates the position of piston 52.Once find that piston 52 has arrived decelerate position, control circuit 61 deceleration pistons 52.In the time that trigger switch 22 is closed, piston 52 is stopped at the rest position of being set by stop position setting device 75 and the operation that finishes jigsaw 1 by control circuit 61.

As the alternative of the position of rotation of detection rotor 3A, terminal voltage checkout gear 77 can be set and replace hole IC 65,66 and 67, for detection of the terminal voltage (induced voltage) between the stator winding 3C of motor 3, as shown in Figure 3.In this case, control circuit 61 is according to the position of rotation of the terminal voltage detection rotor 3A of motor 3 and rotating speed (without the method for sensor).Terminal voltage checkout gear 77 can so be configured to again obtain terminal voltage between stator winding 3C as logical signal by filter.

Next, describe and how to control in the present embodiment and the piston 52 that slows down (motor 3) with reference to Fig. 4.

In the present embodiment, any in the positional information of the rotor 3A of the positional information from position sensor 24 of control circuit 61 based on piston 52 and motor 3 or position that both calculate piston 52.According to the positional information of piston 52, in the time that piston 52 arrives assigned address, control circuit 61 is controlled rotating speed or the anglec of rotation of motor 3.Like this, in jigsaw, vibration and noise reduce, and workability improves.

In the present embodiment, use decelerate position setting device 76 that motor 3 is set, so that motor 3 reduces speed now in the position that approaches two dead points (before arriving two dead points).

Control circuit 61 passes through the rotation of the handover operation control motor 3 of the thyristor 62A that controls FET drive circuit 62, thereby piston 52 can be moved both vertically.Suppose motor 3 rotating speed (First Speed) rotation to be arranged by speed setting device 72 at present.Control/computing unit 61A monitors the positional information from position sensor 24 of piston 52 all the time.When position sensor 24 and piston position testing circuit 74 detect that piston 52 is approaching near but when position before arriving two dead points of the each circulation for moving both vertically, control/computing unit 61A controls thyristor 62A, thereby motor 3 can be slowed to the second speed slower than First Speed.

Particularly, as shown in Figure 4, when piston 52 from top dead-centre (at t=0) in the time that bottom dead centre moves, motor 3 rotates with First Speed.In the time detecting piston 52 and arrived the decelerate position that (or passing through) specified by decelerate position setting device 76, be the position alpha 1 before bottom dead centre, control/computing unit 61A (position detection part 61B) will output to the thyristor 62A of FET drive circuit 62 for the signal that the rotating speed of motor 3 is slowed to second speed from First Speed.Like this, the rotating speed of motor 3 slows to second speed at position alpha 1 place from First Speed.

Two dead points place that changes its direction of motion at piston 52 has inevitably produced noise and vibration.Therefore, preferably, the rotating speed of motor 3 slows down near two dead points, particularly the position before arriving each dead point.Use this configuration, the position that the inertia energy (kinetic energy) of motor 3 switches in the direction of motion of piston 52 can be reduced, thereby allows to suppress most effectively noise and vibration.

With reference to figure 4, L1 represents that the rotating speed of motor 3 maintains the situation that First Speed is constant.L2 represents that the rotating speed of motor 3 slows to the situation of second speed from First Speed at position alpha 1 place.In the situation of L1, piston 52 is moved to bottom dead centre from top dead-centre needs period of time T.On the other hand, in L2 situation, piston 52 is moved to bottom dead centre from top dead-centre needs time durations T+ Δ T.

Here, the amount of exercise of piston 52 is defined as the Δ X of (marginal period of time) Δ t of per cycle crash time.Second speed hypothesis is set to equal 40% speed of First Speed.In this case, particularly, be at 40% of the Δ X at First Speed place at the Δ X at second speed place.Suppose that mass M is identical, the kinetic energy from position alpha 1 to bottom dead centre can be restricted to the speed of being proportional to square, for L1 situation, 0.5 × M × (Δ X/ Δ is t) ².Therefore,, in Fig. 4, for L2 situation, the kinetic energy from position alpha 1 to bottom dead centre is that 0.5 × M × (0.4 × Δ X/ Δ t) ², result be L1 kinetic energy 16%.At bottom dead centre place, the velocity changeabout of piston 52, thus inevitably produce and impact.Because kinetic energy in the situation of L2 only has 16% of the kinetic energy of L1, time of impacting in the situation of L2 kinetic energy at place also reduces to 16% of kinetic energy in the situation of L1.In this way, in the situation that underspeeding, the impact producing at the time place of the variation of the velocity of piston 52 can be suppressed effectively.

In the time detecting that piston 52 has reached (passing through) bottom dead centre, the switching signal H1-H6 of control/computing unit 61A (speed controlling portion 61C) output instruction First Speed is to the thyristor 62A of FET drive circuit 62.In the time that piston 52 passes through bottom dead centre, the rotating speed of motor 3 accelerates to First Speed thus.

The piston position signal that control/computing unit 61A exports according to position sensor 24 detects that piston 52 has reached bottom dead centre.In addition, storage device 64 piston 52 that can prestore moves to the needed time cycle of any dead point from each decelerate position.Move to the required time cycle of bottom dead centre by measure piston 52 with timer 78 from a decelerate position (α 1), and then, by more measured time cycle and the time data prestoring, control/computing unit 61A can detect piston 52 and reach bottom.Also alternatively, storage device 64 can be stored the time range (preset range in stroke amount S) of known vibration and noise generation.Further alternatively, storage device 64 can use timer 78 to count and store each time cycle that moves to a dead point from a decelerate position of piston 52 according to the signal from position sensor 24.Control/computing unit 61A can use this time cycle of being stored by storage device 64 position for detection of piston 52.

In the present embodiment, the rotating speed of motor 3 (First Speed) can be configured to arrange in multiple stages.Therefore, control/computing unit 61A can calculate the time cycle that piston 52 need to slow down based on speed and decelerate position are set, and this time cycle is stored in storage device 64.In this way, control/computing unit 61A can control according to the stored time cycle rotating speed of motor 3.This configuration allows jigsaw 1 to control reliably motor 3 and does not consider the speed that arranges of motor 3, thereby suppresses the generation of vibration and noise.The workability of jigsaw 1 also can improve.

In the present embodiment, in the time that piston 52 speed have approached vibration and noise and can become near very large region (be bottom dead centre), the rotating speed of motor 3 is configured to slow to second speed from First Speed, and after piston 52 is by bottom dead centre, adds near First Speed from second speed subsequently.Like this, owing to even once also not being configured to remain on the second speed of minimizing by the rotation of motor after slowing down 3 at motor 3, therefore can keep improve workability and suppress vibration and noise.

Similarly, in the time that piston 52 moves to top dead-centre from bottom dead centre, the rotating speed of motor 3 slows to second speed at position alpha 2 places from First Speed, as shown in Figure 4.The phase place of the phase place of this position alpha 2 and position alpha 1 has the phase difference of 180 degree.In other words, position alpha 2 is near position top dead-centre but before top dead-centre.

In the time that piston 52 passes through top dead-centre, control/computing unit 61A controls thyristor 62A, so that the rotating speed of motor 3 accelerates to First Speed again from second speed.Notice, decelerate position α 1 may be not identical to the distance between top dead-centre with decelerate position α 2 to the distance between bottom dead centre.Decelerate position setting device 76 can be set to differing from each other by each decelerate position (α 1 and α 2).

If the rotating speed of motor 3 (First Speed) is set to jigsaw 1 and can produce vibration and also there is no such speed of noise, even if or vibration and noise produce also lower such speed, motor 3 does not need to slow down, no matter the setting of decelerate position setting device 76.For example, storage device 64 can prestore and can not produce the rotating speed of vibration and noise.If decelerate position setting device 76 setting is equal to or less than the rotating speed of the speed of prestoring, controls/computing unit 61A controls that motor 3 does not slow down and regardless of the specified rotating speed of decelerate position setting device 76, thereby causes the improvement of the workability of jigsaw 1.

Alternatively, reset switch can be provided for resetting and be stored in piston 52 in storage device 64 and decelerate position, deceleration time and the positional information of motor 3.In this case, when each user uses jigsaw 1, each above-mentioned information can be configured to reset by reset switch.Therefore, always use up-to-date information control motor 3.

As mentioned above, jigsaw 1 is controlled to make, when piston 52 moves reciprocatingly (from top dead-centre, to the decelerate position α 1 before bottom dead centre, then arrive bottom dead centre, then arrive top dead-centre decelerate position α 2 before, and turn back to top dead-centre) time, in the time that piston 52 arrives assigned address α 1 and α 2, the rotating speed of motor 3 slows down.When by repeating this moving both vertically when cutting workpiece, jigsaw 1 can be suppressed at two dead points place and produce and impact, and causes the workability improving.Note, as in the present embodiment, while alternately adopting First Speed and second speed when the generation in order to suppress noise and vibration, as shown in Figure 4, than the situation of L1, the time cycle of piston 52 (for L2) becomes large 2 Δ T.But this cycle is small enough to that the workability of jigsaw 1 is had to little impact.If workability is had to some impacts, First Speed can be set up faster in advance.

Provide in the time of jigsaw 1 shut-down operation the how explanation of control piston 52 (blade 7) below.

If blade 7 is still outstanding from substrate 4 in the time that user finishes to use jigsaw 1, blade 7 may become the obstacle in the time holding or transport jigsaw 1.Therefore, be configured to according to the control circuit 61 of the present embodiment the position that control piston 52 stops at top dead-centre or approaches top dead-centre, as shown in Figure 5.

When control circuit 61 detects that trigger switch 22 is no longer when the driving signal of output motor 3, in the time that cut workpiece finishes, the switching signal of control circuit 61 output semiconductor switch element 62A is to FET drive circuit 62, and the position signalling of position-based sensor 24 is observed the position of piston 52 simultaneously.In the time that detection piston 52 has reached assigned address (no matter being in top dead-centre or near position top dead-centre), for example, top dead center or in Fig. 4 the position of α 2, control/computing unit 61A stops providing switching signal to FET drive circuit 62 or stops forcibly drive motor 3.Like this, piston 52 can stop at the position shown in Fig. 5.Additionally, control/computing unit 61A can stop drive motor 3 before piston 52 reaches assigned address.

On the contrary, in the time that piston 52 stops at top dead-centre or near position top dead-centre during at allowing blade replacement 7 more, this replacing operation will cause low workability, because substrate 4 covers blade 7.Therefore, be provided with stop position setting device 75 according to the jigsaw 1 of present embodiment, for allowing piston 52 to switch its stop position.Adopt stop position setting device 75, control/computing unit 61A can control motor 3, to can stop at top dead-centre or piston 52 moved to bottom dead centre (as shown in figs. 1 and 4) after near position top dead-centre or approach the position (position alpha 1 of Fig. 4) of bottom dead centre at piston 52.

In addition, storage device 64 can be stored instruction stop position setting device 75 and arrange the information (for example,, until the stop position required time cycle of piston 52) of the position that piston 52 stops.In this case, the position of piston 52 when control/computing unit 61A detects trigger switch 22 and closes according to position sensor 24.Control/computing unit 61A uses timer 78 to calculate from the detected position of piston 52 to the needed time of stop position of storing subsequently, and control piston 52 stops in specified location.

Still selectively, replacement provides stop position setting device 75, control/computing unit 61A to carry out control piston 52 according to the signal of exporting from trigger switch 22 and is parked in bottom dead centre or near position bottom dead centre.Specifically, in the time that user depresses the trigger 22A of trigger switch 22 lightly, in the time that control/computing unit 61A detects the signal from trigger 22A, control/computing unit 61A detects the position of piston 52 according to position detection part 61B (position sensor 24 and piston position testing circuit 74), thereby the position of control piston 52 arrives assigned address.

Still selectively, stop position setting device 75 not only can be between top dead-centre and bottom dead centre the position of switching piston 52, but also can for example, as the device (rotating disk or switch) of stop position that piston 52 is set.

As mentioned above, in the time that stop position setting device 75 is rotating disk, user can adjust rotating disk to the stop position of expecting.In the time that stop position setting device 75 is switch, and while being provided with multiple switch especially, user can be according to the stop position depress switch of specifying.In the time that stop position setting device 75 only arranges a switch, user can arrange by the predetermined number of times of depress switch the stop position of piston 52.Stop position signal (from the signal of position sensor 24, the next signal since hole IC 65,66 and 67) based on piston 52, control/computing unit 61A can control motor 3, so that piston 52 can be parked in specified location.

If there is no need to arrange the stop position of piston 52, control/computing unit 61A can control motor 3, so that piston 52 can stop at specified location in the time that trigger switch 22 is closed.In this case, in the time that user depresses reset switch (not shown) or adjusts stop position setting device 75 (position of unnecessary setting when representing that piston 52 is rotating disk), controls/computing unit 61A receives the setting of signal with the position of cancellation piston 52.

Before trigger switch 22 is opened,, before user starts to operate jigsaw 1, stop position setting device 75 there is no need to arrange the stop position of piston 52.Instead, in cutting operation process or afterwards, the stop position of piston 52 can arrange by stop position setting device 75.In this way, user can determine where necessary and stop wherein piston 52, thereby improves the workability of jigsaw 1.

In operating process, how to control jigsaw 1 with reference to the flowchart text in Fig. 6 below.Note that position sensor 24 is assumed that the position for detection of piston 52 in this example as shown in the flow chart of Fig. 6.

First,, in S01, modulator VR (speed setting device 72) arranges speed for motor 3.In S02, control circuit 61 determines whether to activate trigger switch 22 by user.If determine and do not activate trigger switch 22 (S02: no) because user does not operate trigger 22A, flow process turns back to S01.

In the time determining that in S02 user has operated trigger 22A with activation trigger switch 22 (S02: be), in S03, control circuit 61 (comprising as shown in Figure 4, control/computing unit 61A of speed controlling portion 61C) output is arrived FET drive circuit 62 (to thyristor 62A) for the signal (switching signal H1-H6) of drive motor 3.Then control circuit 61 controls battery 23 to supply power to motor 3, thereby at the speed rotating motor 3 of specifying with modulator VR.

In S04, control circuit 61 is determined and is put sensor 24 whether position has detected piston 52.In other words, control circuit 61 detects piston 52 and whether is in the position that position-detection sensor 24 can detect, and that is to say, approaches position top dead-centre or bottom dead centre.As previously mentioned, replacement, position sensor 24 can be configured to always detect the position of piston 52.

If position sensor 24 does not detect piston 52 (S04: no), flow process turns back to S03.If position sensor 24 detects piston 52 (S04: be),, in S05, control/computing unit 61A (position detection part 61B) determines the position of piston 52 and specifies the position of rotation of motor 3 according to the terminal voltage between stator winding 3C or hole IC 65,66 and 67.

In S06, control/computing unit 61A (position detection part 61B) is based on determining whether that from the output signal of position sensor 24 piston 52 has reached the decelerate position of being set by decelerate position setting device 76 subsequently.In the present embodiment, control/computing unit 61A determines that whether piston 52 is by the position alpha 2 before position alpha 1 or top dead-centre before bottom dead centre.Storage device 64 pre-stored about piston 52 with respect to each the information (such as the time cycle, position signalling, the position signalling of motor 3 etc. of piston 52 that arrange according to rotating speed) of current position in position alpha 1, α 2, top dead-centre and bottom dead centre.Control/computing unit 61A determines that by actual detecteding value with pre-stored value piston 52 has reached assigned address.

In the time that control/computing unit 61A does not detect piston 52 by position alpha 1 or position or α 2 (S06: no), flow process turns back to S03.On the other hand, when control/computing unit 61A detects that piston 52 is when any (S06: be) by position alpha 1 and α 2, in S07, control/computing unit 61A output switching signal H1-H6 is to FET drive circuit 62, to the rotating speed of motor 3 can be slowed to the low speed of rotating speed arranging than the modulator VR in S01.Here, multiple speed that arrange that storage device 64 can be specified according to modulator VR are stored the rotating speed being slowed down.

Subsequently, in S08, the signal of control/computing unit 61A based on exporting from position sensor 24 determine piston 52 whether by top dead-centre and bottom dead centre any one.Alternatively, control/computing unit 61A can be according to the current location that is stored in the information calculating piston 52 in storage device 64.

In the time that definite piston 52 does not both pass through bottom dead centre (S08: no) by top dead-centre yet, flow process turns back to S09 and motor 3 remains on the speed being slowed down.In the time piston 52 being detected by top dead-centre or bottom dead centre (S08: be), in S09, control/computing unit 61A (speed controlling portion 61C) gauge tap signal H1-H6 is to the output of FET drive circuit 62, so that the rotating speed of motor 3 can be accelerated the speed of being set by modulator VR in S01 that reaches.

Subsequently, in S10, control circuit 61 determines whether user has operated trigger 22A.In the time that user operates trigger 22A and therefore trigger switch 22 is activated (S10: be), flow process turns back to S03 and repeats the step from S03 to S10.

In the time that control circuit 61 determines that in S10 trigger switch 22 is not activated (S10: no) by user, in S11, control/computing unit 61A (speed controlling portion 61C) gauge tap signal H1-H6 is to the output of FET drive circuit 62, reduce the power supply supply from battery 23 to motor 3, and the rotating speed of decelerator 3.

In S12, control circuit 61 is according to the position of the signal detection piston 52 of position sensor 24.In the time the position (S12: no) of piston 52 can not being detected, flow process turns back to S11.Position sensor 24 can be configured to always monitor the position of piston 52.

In the time detecting the position (S12: be) of piston 52, in S13, control/computing unit 61A (position detection part 61B) determines whether piston 52 has reached the stop position of the motor 3 being arranged by stop position setting device 75.In the present embodiment, control/computing unit 61A determines whether piston 52 has reached top dead-centre or near the position of top dead-centre.

Also do not arrive while approaching the position (S13: no) of top dead-centre when piston 52 has not both arrived top dead-centre, flow process is returned to S11.On the other hand, in the time determining that piston 52 has reached top dead-centre or approached the position (S13: be) of top dead-centre, in S14, control/computing unit 61A (speed controlling portion 61C) controls the switching signal H1-H6 that outputs to FET drive circuit 62, so that motor can stop operating 3, thereby fully stop the rotation of the output shaft of motor 3.Then control circuit 61 stops controlling the operation of jigsaw 1.Like this, in the time that user can use jigsaw 1, piston 52 can be placed on top dead center or in the position that approaches top dead-centre.

In the time of allowing blade replacement 7 more, in S13 and S14, control/computing unit 61A controls blade 7 (piston 52) to reach bottom dead centre.By handling stop position setting device 75 or pulling lightly trigger 22A once, user can be switched to bottom dead centre from top dead-centre by the stop position of piston 52.Use this configuration, because blade 7 is located bottom dead centre place, user can easily change the blade 7 on the maintaining part 52A that is arranged on piston 52.

The variation of present embodiment is described with reference to Fig. 8 below.In variation, motor 3 is driven by AC power 90, and replaces employing position sensor 24, according to the position of the position of rotation of motor 3 and rotating speed detection piston 52.

In this variation, the terminal voltage checkout gear 77 (seeing Fig. 3) of the terminal voltage between the hole IC 65,66 and 67 of the position based on detection rotor 3A and detection stator winding 3c is controlled position of rotation and the rotating speed of motor 3.In the time adopting brushless motor (motor 3), position of rotation and the rotating speed of inevitable requirement motor 3 (rotor 3A).Therefore, only detect the position of piston 52 according to motor turn signal, and do not adopt position sensor 24, can contribute to reduce parts, thereby suppress the cost of jigsaw 1 required parts.

As shown in Figure 8, variation of the present invention is from the different of preferred embodiment shown in Fig. 7, delete position sensor 24 and piston position testing circuit 74, and use AC power 90 to replace battery to provide electric power to motor 3.Owing to adopting AC power 90, current transformer 80, a pair of resistance 81 and 82 and voltage detecting circuit 83 therefore in this variation, are added.In addition,, in this variation, display unit 91 and reference point setting device 92 have also been increased.

Current transformer 80 will convert DC current to from the alternating current of AC power 90.Resistance 81 and 82 detects the DC current of being changed by current transformer 80.Voltage detecting circuit 83 detects DC current and output detection signal arrives control/computing unit 61A.Display unit 91 shows the configuration information of jigsaw 1.This reference position setting device 92 arranges the reference position of piston 52.This reference position setting device 92 comprises switch.

When only according to the position of the positional information calculation piston 52 of motor 3, the inevitable once rotation corresponding to motor 3 (rotor 3A) of the once reciprocating motion (time 0 from Fig. 4 is to time 2T) of piston 52.Therefore, the position of the position of piston 52 and motor 3 needs associated with each other.Hereinafter, how explanation is arranged to the position of piston 52 and motor 3.

Load and transport (or assembling) during at jigsaw 1, external equipment turning motor 3, for detection of the position of position of rotation and the piston 52 of rotor 3A.Such external equipment can be based on piston 52 and is arranged on distance between the position sensor in external equipment and detects the position of piston 52.Alternatively, spring can be connected to piston 52, so that external instrument can the tensile force based on spring detects the position of piston 52.Also can apply other detection methods.

Still selectively, replace and use such external equipment, can determine at first the position relationship between piston 52 and motor 3 at 1 jigsaw itself.

First, piston 52 navigates to reference position, for example, and to top dead-centre.Now, in order to make the reference position (being top dead-centre) of control/computing unit 61A (storage device 64) storage piston 52, user operates reference position setting device 92.Replace user, can use external equipment, for reference position being set by the position of monitoring piston 52.Control/computing unit 61A (storage device 64) piston 52 that prestored is the rpm that once moves back and forth required motor 3.As an example, suppose that motor 3 rotates ten times during once the moving both vertically of piston 52 here.

In the time that motor 3 rotates, position of rotation and the rotating speed of hole IC 65,66 and 67 detection rotor 3A.Hole IC 65, the 66 and 67 output pulse signal relevant to the polarity (north and south poles) of rotor 3A.Rotor position detection circuit 68 and speed detect circuit 69 will be converted into the pulse signal of the form that control/computing unit 61A can identify from the pulse signal of hole IC 65,66 and 67 output, and then by its input control/computing unit 61A.In the situation of Fig. 8, because rotor 3A is provided with a pair of north and south poles, the variation in hole IC 65,66 and 67 bases in each polarity carrys out output signal.Specifically, each hole IC is two pulses of each rotation output of rotor 3A, and therefore, as a whole, six pulses will be output.Therefore, in the time that motor 3 rotates ten times, 20 pulses of each hole IC output.That is to say 60 pulses of hole IC 65,66 and 67 entirety outputs.The quantity of pulse in the time that piston 52 is positioned at the reference position being arranged by reference position setting device 92 of also prestoring control/computing unit 61A equals zero.In this way, control/computing unit 61A can be according to rotation information (the being umber of pulse) control piston 52 of motor 3 during of piston 52 moves both vertically.If need to increase the umber of pulse that is input to control/computing unit 61 for the control more accurately of piston 52, extra frequency divider can be set for the umber of pulses from hole IC65,66 and 67 outputs.

At the time of shipment of jigsaw 1, the reference position of piston 52 is arranged by the setting device 92 of reference point, and storage device 64 be stored in piston 52 start once to move back and forth from reference position during from the number of pulses of hole IC 65,66 and 67 outputs.During cut workpiece, in the time that user handles reference position setting device 92, control/computing unit 61A can be according to the rotation information of motor 3, that is, and and according to the position of the pulse signal detection piston 52 from hole IC 65,66 and 67 outputs.For example, if from hole IC 65, the pulse of 66 and 67 outputs adds up to 30, control/computing unit 61A compares the number of pulses detecting (30 subpulse) and the pulse information being stored in storage device 64, and definite piston 52 reached corresponding to once move back and forth during by the position of the half of the umber of pulse being output, that is to say, piston 52 has reached dead point.

In the time that piston 52 repeatedly moves both vertically, each umber of pulse becomes 60 integral multiple, and control/computing unit 61A determines that piston 52 has arrived reference position.For example, be 3000rpm if speed setting device 72 arranges the rotating speed of motor 3, motor 3 rotation per second 50 times.Therefore, during this period, piston 52 carries out five times and moves both vertically.During moving both vertically for five times, 300 pulse signals of hole IC 65,66 and 67 outputs.Control/computing unit 61A carries out the number of pulses of the number of pulses detecting and storage, and detects the position of piston 52.Control/computing unit 61A also can be by from hole IC65,66 and 67 output number of pulses with compare from the signal of decelerate position setting device 76 and stop position setting device 75, the signal relevant to number of pulses from hole IC 65,66 and 67 compares, and reached decelerate position and stop position thereby detect exactly piston 52.

In this way, control/computing unit 61A can control motor 3, so that motor 3 can slow down and stop in specified location.As mentioned above, even without position sensor 24 (with the piston position testing circuit 74 shown in Fig. 7), control/computing unit 61A also can only detect the position of piston 52 according to the rotary position information of motor 3 (3A rotor).

Hereinafter, be used for according to the method for the position of the positional information control piston 52 of motor 3 describing in detail.

User operates trigger switch 22 to start turning motor 3.Input the signal (pulse signal) of the position of rotation of the instruction motor 3 being detected by hole IC 65,66 and 67 via rotor position detection circuit 68 to control circuit 61.The position that the motor position signal (umber of pulse) that control/computing unit 61A basis detects and the positional information (umber of pulse) that is stored in the motor in storage device 64 are calculated piston 52.For example, if 20 pulses detected, control/computing unit 61A determines that piston 52 not yet arrives bottom dead centre (its umber of pulse is 30).

Meanwhile, control/computing unit 61A determines whether piston 52 has reached the appointment decelerate position of being specified by decelerate position setting device 76, such as the position before top dead-centre with in lower position before dead.In the time determining that decelerate position has been set to the position corresponding to umber of pulse 20, controls/computing unit 61A exports (switch) signal H1-H6 to FET drive circuit 62, for the rotating speed of the motor 3 that slows down.Subsequently, when detecting while being 30 from the umber of pulse of hole IC 65,66 and 67, control/computing unit 61A controls motor 3 and accelerates.

Closed when detecting trigger switch 22, control/computing unit 61A determines whether to represent that from hole IC65,66 and 67 pulse digit converter piston 52 has reached the appointment stop position (for example top dead-centre) of being specified by stop position setting device 75.In the time that definite piston 52 has reached stop position, control/computing unit 61A controls motor 3 and stops, so that piston 52 can stop at rest position.Like this, though setting position sensor 24 not, also can be according to the position that is pre-stored in the positional information calculation piston 52 that the position with piston 52 in storage device 64 is associated of motor 3.

In addition, jigsaw 1 can also be provided with storage resetting means and storage and reconfigure device.Storage resetting means resets about the information that is stored in the position relationship in storage device 64 between piston 52 and motor 3.Storage reconfigures device and reconfigures the position relationship between piston 52 and motor 3.Adopt storage resetting means and storage to reconfigure device, in storage device 64, the old data of storage can be deleted, and storage device 64 can store latest data therein, makes it possible to control more accurately motor 3.Note, stop position setting device 75 and decelerate position setting device 76 also can be used as storage resetting means and storage reconfigures device.If stop position setting device 75 and decelerate position setting device 76 are rotating disks, these devices 75 and 76 can be configured to that rotating disk pre-determined number is switched to storage resetting means and storage reconfigures any in device by rotating continuously.In the situation that stop position setting device 75 and decelerate position setting device 76 are switch, the time cycle during device 75 and 76 can be configured to be depressed according to each switch reconfigures between device and switches in storage resetting means and storage.

When storage being set while reconfiguring device, the reconfiguring of the position relationship between external equipment operating motor 3 and the piston 52 using can be used in shipment jigsaw 1 time.But, reconfigure and can also on the jigsaw 1 with storage device 64, carry out.In this case, need position sensor 24 and piston position testing circuit 74.

In the time that operation store reconfigures device, control circuit 61 turning motors 3, and no matter the state of trigger switch 22.Control/unit of account 61A reads the positional information that is used to specify angle rotor 3A from the terminal voltage of hole IC 65,66 and 67 or stator winding 3C, and this positional information is stored in storage device 64.Meanwhile, control/unit of account 61A reads the positional information relevant to described specified angle of piston 52 from position sensor 24, and this positional information is stored in storage device 64.Control circuit 61 stops the rotation of motor 3 and stops this storage operation.Like this, as long as the position relationship between motor 3 and piston 52 stores, even if position sensor 24 damages for some reason, control circuit 61 can be according to the positioning motor of piston 52 3, thus the workability of raising property jigsaw 1.

In addition,, owing to being provided with display unit 91 (as display or LED) in this variation, user can confirm the various information of jigsaw 1 intuitively.Display unit 91 can show, for example, shows the information of store operation well afoot, the appointment rotating speed of motor 3, the position of piston 52.Therefore, workability also will be strengthened.In addition demonstration information, can conveniently be confirmed the state of storage method and decelerate position and stop position.

Although, with reference to its detailed description of the invention explanation the present invention, it will be understood by those skilled in the art that in the situation that not deviating from scope of the present invention and can have various variations.

For example, not only in the top dead-centre side of piston 52, a position sensor (position sensor 24) is set, in bottom dead centre side, another position sensor also can be set.In this case, can detect more accurately the position of piston 52.In addition, also can adopt the sensor of other types as position sensor 24, instead of proximity transducer.

In addition, except the jigsaw 1 as cutting tool, the present invention also goes for having other reciprocating electric tool of the end cutter head being in vertical motion, as wearing type saw cutter (reciprocating saw), hammer, hammer drill and desk-top jigsaw.

Industrial usability

The present invention is applicable to reciprocating electric tool, such as jigsaw, and has the electric tool of any type of reciprocal end cutter head.

Description of reference numerals

1 reciprocating electric tool

2 shells

3 brushless motors

6 control device

24 position sensors

52 pistons

Claims

1. a reciprocating electric tool (1), comprising:

Brushless motor (3);

Piston (52), is driven by brushless motor, and moves back and forth between top dead-centre and bottom dead centre, and cutting blade (7) is installed to one end of piston on reciprocating direction; With

Control device (6), for the rotating speed of the Position Control brushless motor based on piston, wherein

When piston reaches close to bottom dead centre with just when the position before bottom dead centre, the slow down rotating speed of brushless motor of control device.

2. reciprocating electric tool according to claim 1, also comprises:

Checkout gear (24), for detection of the position of piston.

3. reciprocating electric tool according to claim 2, wherein:

Checkout gear is the sensor that detection piston reaches precalculated position.

4. the reciprocating electric tool described in any one according to claim 1-3, wherein:

Control device is according to the slow down rotating speed of brushless motor of the position of piston.

5. reciprocating electric tool according to claim 4, wherein:

When piston is by after described arbitrary dead point, control device is accelerated the rotating speed of brushless motor.

6. reciprocating electric tool according to claim 4, also comprises:

Decelerate position setting device, for being provided for the decelerate position of the rotating speed of brushless motor, wherein according to the position of piston

Control device is according to the slow down rotating speed of brushless motor of the decelerate position that arranged by decelerate position setting device.

7. reciprocating electric tool according to claim 4, wherein, control device maintains brushless motor at the rotating speed place of reduction, until piston is by arbitrary dead point.

8. reciprocating electric tool according to claim 4, wherein, after the rotating speed of brushless motor reduces, maintains low speed state by the rotation of brushless motor in control device predetermined time cycle.

9. reciprocating electric tool according to claim 6, also comprises:

Storage device, the multiple decelerate position information that arrange for storing decelerate position setting device, wherein

The decelerate position of control device based on being arranged by decelerate position setting device calculated the cycle very first time that brushless motor is maintained to low speed state, and maintain the cycle very first time in cycle as slowing down and be stored in storage device what calculate, and control device maintains deceleration regime by brushless motor before maintaining period expires being stored in deceleration in storage device.

10. reciprocating electric tool according to claim 9, wherein:

Control device calculates the second time cycle that reaches first described dead point after the rotating speed of the brushless motor that slows down based on decelerate position information, and the second time cycle calculating is stored in storage device, and the piston that is rotated in of brushless motor passes through to be accelerated behind described dead point.

11. reciprocating electric tools according to claim 6, also comprise:

Speed setting device, for arranging the rotating speed of brushless motor; With

Storage device, the multiple decelerate position that arrange for storing decelerate position setting device, wherein

The rotating speed of the decelerate position of control device based on being arranged by decelerate position setting device and the brushless motor that arranged by speed setting device calculates holds time the cycle for the deceleration that brushless motor is maintained to deceleration regime, and the deceleration cycle of holding time calculating is stored in storage device.

12. reciprocating electric tools according to claim 6, also comprise:

Speed setting device, for arranging the rotating speed of brushless motor; With

Storage device, holds time the cycle for the deceleration that brushless motor is maintained to deceleration regime for the signalization based on from speed setting device and decelerate position setting device is pre-stored, wherein

Control device is according to the slow down rotation of brushless motor of the deceleration cycle of holding time in storage device of being stored in.

13. reciprocating electric tools according to claim 12, wherein

Described storage device is also for storing the desired speed of brushless motor, wherein

When the rotating ratio of the brushless motor being arranged by speed setting device is stored in desired speed in storage device when low, control device maintains fixing rotating speed by the rotation of brushless motor and no matter from the output of decelerate position setting device.

14. reciprocating electric tools according to claim 6, also comprise:

Reset apparatus, the decelerate position of the brushless motor having been arranged by decelerate position setting device for resetting.

15. reciprocating electric tools according to claim 1, also comprise:

Device for detecting rotational position, for detection of the position of rotation of brushless motor; With

Storage device, for the position of the position of rotation corresponding to brushless motor based on piston, the position data relevant with the position of piston to the position of rotation of brushless motor that prestore, wherein

The position of rotation of the brushless motor based on being detected by device for detecting rotational position and be stored in the position data in storage device, control device calculates the position of piston.

16. reciprocating electric tools according to claim 15, also comprise:

Storage resetting means, for the position data relevant with the position that is stored in storage device of piston to the position of rotation of brushless motor that reset.

17. reciprocating electric tools according to claim 15, also comprise:

Storage reconfigures device, for reconfiguring the position data relevant with the position that is stored in storage device of piston to the position of rotation of brushless motor.

18. according to the reciprocating electric tool described in any one in claim 1,2,3 and 15, also comprises:

Battery, for supplying with electric power to brushless motor.

19. according to the reciprocating electric tool described in any one in claim 1,2,3 and 15, also comprises:

AC power, for supplying with electric power to brushless motor.

20. 1 kinds of reciprocating electric tools, comprising:

Brushless motor;

Piston, is driven by brushless motor, and moves back and forth between top dead-centre and bottom dead centre, and end cutter head is installed to one end of piston on reciprocating direction, for passing through the reciprocating motion cut workpiece of end cutter head; With

Control device, for the rotating speed of the Position Control brushless motor based on piston, wherein, control device is controlled brushless motor in the time that the reciprocating motion of end cutter head stops, so that piston stops at pre-position.

21. reciprocating electric tools according to claim 20, also comprise:

Stop position switching device shifter, for being switched to the stop position of piston near of described dead point.

22. reciprocating electric tools according to claim 20, also comprise:

Stop position setting device, for arranging the stop position of piston, wherein

Control device control piston, to stop at piston the described pre-position being arranged by stop position setting device.

23. reciprocating electric tools according to claim 22, wherein,

Stop position setting device output signal is to control device, and described signal is used for making piston to stop near arbitrary dead point, and

Control device control brushless motor, stops piston with basis from the output signal of stop position setting device.

24. reciprocating electric tools according to claim 23, wherein,

Stop position setting device output switching signal is to control device, and described switching signal is used for the stop position of piston to be switched to the position near another dead point, and

Control device is according to switching signal control brushless motor.

25. 1 kinds of reciprocating electric tools (1), comprising:

Brushless motor (3);

Piston (52), drive and move back and forth between top dead-centre and bottom dead centre by brushless motor, cutting blade (7) is installed to one end of piston on reciprocating direction, and cutting blade is configured to cut workpiece in the time shifting to top dead-centre from bottom dead centre; With

Control device (6), for based on piston the position during the reciprocation period of piston control the rotating speed of brushless motor, wherein when piston reaches close to bottom dead centre with just when the position before bottom dead centre, the slow down rotating speed of brushless motor of control device.

26. 1 kinds of reciprocating electric tools (1), comprising:

Brushless motor (3);

Piston (52), is driven and is moved back and forth between two dead points by brushless motor, and end cutter head (7) is installed to one end of piston on reciprocating direction, for passing through the reciprocating motion cut workpiece of end cutter head; With

Control device (6), for controlling brushless motor piston is stopped to predetermined stop area in the time that the reciprocating motion of end cutter head stops.